Mortality Rate = (Deaths / Population) × 100
Mortality rate = (number of deaths / total population at risk) × 100 over a defined time period. Acceptable mortality rates vary by species and age: dairy calves <5%/year, feedlot cattle <1.5%, poultry layers 5-8%/year, swine nursery <3%. High mortality signals disease outbreaks, poor nutrition, environmental stress, or management issues. Related metrics: morbidity rate (illness), case fatality rate (deaths among sick animals), and specific mortality (by age/cause). Monitoring mortality trends helps veterinarians and farmers identify problems early and evaluate the effectiveness of health interventions.